I've read many, many posts, yet still I am wondering if my approach will work. I have a 1X6 fir t&g subfloor laid diagonally over 2x10 joists. On top of this is a 1/2 particleboard underlayment. I would like to put a 5/8 plywood underlayment down over the PB (avoiding removing the PB) and then a 3/4 bamboo floor over this using 2" staples and a Bostitch stapler. This approach would line the bamboo floor height perfectly with my tile entry. It's also mch easier to deal with 5/8 plywood over 3/4.

Question, will the plywood layer compensate for the particleboard? Would it be better to go without the plywood, since the staples would then seat more deeply into the T&G subfloor?

Or am I ultimately doomed to removing the PB?

THANKS, THANKS, and THANKS in advance. Lotsa knowledge on this board.

You should NOT install a nailed down floor over particle board, even IF you install plywood over that. The p. board needs to be removed. You maybe able to install your new bamboo flooring directly over your 1 x 6 diagonal subfloor as that is an approved subfloor for nailing into. BTW, I've never seen 3/4" bamboo. Are you sure about that thickness or is it 5/8"?

Hi Gary,

I am new here but have been reading.

I found this, one of your posts below:

There are other, older and not used anymore subfloor systems one may encounter. Such as: 1&1/8" T&G plywood subfloor installed at 90 deg to 4x6 beams spaced 4' oc.
1&1/2" x 5" T&G solid fir deck boards installed at 90 deg. to 4 x6 beams spaced 4' oc.
1x8 solid fir/pine boards installed at 90 deg to joists spaced 16" oc
1" RED-X T&G particle board subfloor installed at 90 deg to joists spaced 2' oc.
3/4" or 5/8" particle board found mostly today in modular and mobile homes.
These subfloors should NOT be removed but overlayed with 1/2" CDX plywood that is well stapled (2" around perimeter and 6" oc.) or glued or screwed. In all cases, subfloors and underlayments are to be flat to within 3/16" in a 10' radius.

When gluing down an engineered floor over a solid lumber subfloor, you will need an underlayment of 3/8" plywood, at least. When gluing down to a plywood or OSB subfloor, many are tempted not to use an underlayment. I prefer to use a 3/8" plywood underlayment over a plywood subfloor when gluing down a wood floor because if the floor needs to be repaired or replaced, it is easier/better with underlayment than with the subfloor.

I hope this clears up many of your questions regarding installing wood floors over wood subfloors.

Regards, Gary



My question is, the quote at the top contradicts it seems this post below here.

My situation is this, I have a 3/4 waferboard subfloor which I guess is the same as particle board. I am installing 5/8 or 9/16 bamboo hardwood with a Bostitch MIII

In the second post of your hear, from what I could determine, you stated to not remove the particle subfloor but rather put 1/2" CDX plywood (not sure what CDX stands for?) on top and screw every 6 inches OC and every 2 inches around perimeter. I have also read to leave a 1/8" gap all the way around every sheet.

On top of this would go 15# felt of Aquabar B paper, then the bamboo.

Please let me know if this is the way. I am in Atlanta, it is on the second floor above a garage.

Many Thanks for clearing things up if you can,


Cheers,

Tibor

First, there is no contradiction. You are misunderstanding the materials and correct procedures.

Waferboard, as you call it, is usually an earlier form of OSB. It is NOT particle board. They are two different products. Also, it is RARE that particle board is used as a SUBFLOOR ( not underlayment ). Only when particle board is used as a SUBFLOOR, should plywood underlayment be used OVER (on top) of it.
In this quote,

I am referring to particle board UNDERLAYMENT, not subflooring, which IS different and should be removed prior to nailing a wood floor over. Some manufacturers consider particle board acceptable for GLUING and floating a floor over but not nailing. Please re-read this thread carefully:
http://www.hardwoodinstaller.com/hardwo ... .php?t=385

Hi Gary,


Thanks for the post and clearing some things up for me.

My subfloor is 17 years old, and I did not know what it was by its markings, that is why I was confused which applies to me.

I just had another look, and this is what I saw as far as markings on my boards:

Grant Wafer Board
Boca No 83-30
Ext Bond P1P1
CMHC ERo 10042 $ 10785

3/4" (not tongue and groove) spaced 1/8 inch on edges.
It is also stamped to use underlayment for ceramic tile.


So based on this, I imagine it best if I put the CDX Plywood 1/2" on top, and stagger it so it is not lined up same way as subfloor, but same direction, so they are staggered, and leave 1/8" gap once again on edges and I should be good.

Many Thanks again for your insight,


Tibor